Wrapped belt



April 28, 1942. A, FREEDLANDER l2,281,148

` WRAPPED BELT VFiled Aug. 25, 1939 3 Sheets-Sheet l ABRAHAML.F/?EEDLA/VDE/? April 28, `1942.1 A, L, FREEDLANDER 2,281,148

WRAPPED BELT Filed Aug. 25, 1939 3 Sheets-.Sheet 2 /A/VEA/TOR AERA HAML. FREEDLANDER.

A T TOR N11-TV5` April 23,1942 `A. l.. 'FREEDLANDER Y 2,281,148

WRAPPED BELT Filed Aug. 25, 1939 3 sheets-sheet s /NVENTOR ABRAHAM L..FREEDL-ANDER BVM@ Z AT Tom/Ys cross section;

l a belt having rectangular shaped Von the underside; i Y l i Figures 9and 10 are detail transverse andlongitudinal sectional .views oi thebelt construction Patented Apr. 1942 UNITED l STATES PATENT oli-FICE li" l powertransmitting belts and more particularly wrapped belts.

Itis an objectot this invention to v -type wrapped belt comprisinggrooves on the undersideso as to produce a belt having improvedexibility and a cooler operating belt.

Another object is to provide an improved cog belt which is very durableandwill develop less heat in operation than the belts of this type,heretofore made.

`provide a i Another object is to` devise a V-type groove belt whichwill have longer life in service and will-constantly transmit drivingpower in `a sxnooth,silent and emcient manner at a lowcost. Anotherobject isto devise a V-type cog belt wherein grooves of improvedconstruction are formed on the inner side to provide a highly flexible.cool runnirigbelt. l Another object is to provide a belt of characterwhereinthe spaced grooves formed on the underside. of the belt areadapted to close i as the belt passes around a pulley of relativelysmall radius fof curvature so as to take up the compressive force actingon the inner sidefof the belt. i y t Another object` isfto provide a`wrapped V-belt which is of balanced crosswise rigidity but is` readilyflexible about atransverse axis having no tendency to twist orbecomerdistorted in opera.` tion. Y M1 Another object is to provide awrapped .cog belt which is adapted tobe bent over relativelysmallpulleys `without developing internal strain in thebody of the belt. i

Referring to the drawings: f Figure l is a perspective sectional `viewenlarged scale ofmy improved belt;

Figures 2, 3 and 4 illustrate diii'erent modiiications of forming thepicot splices for the lay-` ers in constructing the belt; 4, Y

Figure 511s a detail plan view of thebeltiproi vided with grooves on theinner side curved in Figures and 7 aredetail transverse and1onvgitudinal sectional views respectively of the belt constructionshown in Figure 5; Figure 8 is a framentarydetail plan view ofiliustratedinFigure: mure 11 is a fragmentary detail plan view of a beltwherein the grooves are of semi-circular on an grooves formed l Fleurs141s a fragmentary deren view or 1111;.`

other `modification whereinthe .grooves or cogs are of arcuate `shapealong their longitudinal axis;

Figures "l5 and belt construction illustrated in Figure 14;v

Figure -17 `is a detail view of the belt partly broken away showing theprogressive closingtof therooves around the curved portionsof the beltwhen it is'bent;

Figure 18 is a similar view showingthe closing of thegrooves at thebend,` when the beltis bent thr h a small radius of curvature.

Figure trated in Figure 11;

. Figure 20 is a perspective view offa section of the belt havinggrooves on the underside, of

ythe shape showntin Figure 5; i V l view of a sectionof belt havinggrooves as illustrated in Figure 21 is a similar perspective Figure 22is; a similar perspective view of a section of thcbeltV having groovesas shown `in Figure 8i Figure 23 is a view of the ber impregnated rubbercomposition employed in constructing the wrapped belt;

Figure 24 is a similar fragmentaryenlargedl de l v tail view of aflberreinforced rubber composl-` tion, trade named Stiex," used in'makingthe belt. l -1 t Referring to which aredisposedtransversely'therein. Upon shapedcrcss section and extendingtransversely of `theinner surfaces of the belt; i

Figures l2 and 13 are detail transversewand longitudinal sectional viewsrespectively of the belt construction shown in Figure 11;

this layerl is superimposed thestrength band or neutral axis section 26.This section ofthe belt is provided with tightly twisted cords 21 em-v`bedded in rubber making the belt substantially inextensible. Over thissectionris disposed a rubberized fabric layer. 28 to providelongitudinal extensibility with comparativelydittleextensibilitylaterally. The fabricin this instance may be of bias-laidsquare woven textile fabric,

A` wrapper or cover layer `29 comprising layers oi rubberized fabric isdisposed around the body of the belt. This wrapper memberpreferablycomprises several fabric plies lllfwhi'ch are bias wound around the beltbody and cured lthereto forming a unitary beltstructure-` The abuttingends of the layers V25 and 28 are interlockedby picot splices 3lasillustrated in Figure, 1'. This manner of splicing the differentlayers together l. Y overcomes any tendencyof thev4 layers forming` Av4thebelt to pull apart` or draw awayffrom each other at their endswhich would lengthen the 16 `are i detail transverse longitudinalsectional views respectively ofthe 9 is a perspective viewof `asectionlof the beltfcomprising grooves of the shapeillusrragmentaryenlarged detair the drawings in' detail. there 1s illustrated in: Figurel a `belt `which comprises l the compression section 25 formed ofTStiiiex or equivalent rubber composition -reinforced with flncsubstantially` parallel texti1e ,fibersk belt. Other picot-type splicingof the ends of the different layers may be used, such as thatillustrated in Figures 2, 3 and 4 at 32, 33 and 34, respectively.- y

The inner surface of the belt wrapper 29 is provided with spacedgrooves, generally designated 36, which are designed to increase theilexibility of the belt, permitting it to pass over relatively smalldiameter pulleys and in addition function to ventilate the inner surfaceof the belt so as to provide a cool running belt. These groove portionsmay be of different size and cross sectional shape, as illustratedin-Figures19 to 22 inclusive. They substantially confine outwarddistortion or bulging to the wrapper, in passing yaround curves. Bypreventing such bulging or distortion from being communicated to thecompression'section 25, to'any substantial degree, (if at all), the lifeof the belt is substantially lengthened, it being understoodthatrepeated distortions of the belt body intime cause disintegration andrupture of the rubber particles inthe belt layers, finally destroying ormaterially reducing' the usefulness of the belt. i Asshown in all of thesectional views ofthe drawings, with-the'exception of Figs. 23' and 24,and the'persp'ective sectional view, Fig. l, my belt is a' two-part beltcomprising alcompression section 25, and al neutral axis section 26,both of said sections being enclosed in the wrapper 29.

Fig. 1,-however, is a'three-part belt, comprising tension, neutral axis,and compression sections,

enclosed in the same wrapper 29, as my two-part belt. l v

As shown in Figures 5, 6, and 20, the grooves are open only at one end.In Figures 11, l2, I3

employed, as illustrated by the grooves 42 in Figures 14, 15, 16 and 21.Similarly rectangular shaped spacedgrooves 43 may be formedon theunderside of the belt as indicated in Figures 8, 9, 10 and'22.

'I'he material forming the-compression section v 25 is made ofrubber orequivalent resilient materialwhich is reinforced with fine, paralleltextileiibers 45 disposed substantially transversely of the section, asshown in Figure 24. This particular reinforced rubbercomposition isgenerally known in the art as Stiflex." VThe transverse reinforcement inthe material greatly Aenhances the lateral incompressibility thereofwhile offering substantially noresistance to flexing of the sectionabout its transverse axis.

Rubberized fabric making up the layer za in Fig. 1 and cover section 29is preferably made of bias-laid squareA woven rubberized textile fabric46, as illustrated in Figure-23. 'I'he term biaslaid indicatesithat thefiber threadsV are diagonally disposed with respect to both thelongitudi` nal andY transverse axis of the material andthe belt..v'I'his construction substantially increases the tensile strength of thebelt. v

Preferably a four-ply rubberized fabric cover'- ing is employed asshownin Figure 23 and the inner side comprises spaced molded grooves. By

employing groves of different depth, shape and spacing the bendabilityor exibility of the belt may be variedas desired. Further, bypositioning `the neutral axis portion, which comprises the .inextensiblecords 21, near the outer part of the f belt a substantially noiselessoperating belt is provided. l Y

Belts of this construction are preferably formed by layingl one ply onanother around a drum or mold to build up the laminated belt body;there- .after the V-shaped belt is cut from the drum and the wrappercover is folded around the laminated layers and the whole vulcanized toa unitary structure. In the.' case where the belt is built up in aringmold thel walls of the mold will be inclined at an angle to providea-V-shaped belt after vulcanizing. Further the grooves lwhich areformedon the inner side of the belt are preferably molded during the finalvulcanization treatment. y

It will be understood that it is desired to be comprehended within thisinvention such medincations as may be necessary to adapt itto varyingconditions and uses.

Having thus fully described my invention, what I claim as new and desireto secure by Lettersv section including a plurality of parallel laidcords extending longitudinally oi said belt and a wrapper completelyencircling said belt and provided with spaced grooves extending at rightangles to the side walls of the belt and molded on the inner'.

side'thereoL-tlie depth of saidA grooves being less than the depth ofthe underside 'thicknessof the wrapper. l

2. A wrapped belt comprising a tension section formed of superimposedlayers of rubberized fabric made up of bias-laid square woven textilefabric, a neutral axis section comprising a plurality of parallel laidcords extending longitudinally of said belt, a compression sectioncomprising rubber composition reinforced with fine textile fibers whichare disposed substantiallyA parallel and transversely of thelongitudinal axis of -said belt, a wrapper enclosing saidV tension,neutral axis and compression sections of the belt` formed of a pluralityof bias-laid square Vwoven rubberized -fabric layers, said wrapperhaving spaced grooves along the inner side surface which Y extendsubstantially at right angles to the side walls of the belt,'saidgrooves being of less depth than the thickness of said wrapper.

3. A wrapped belt comprising a tension section formed of superimposedlayers'of rubberized fab- Y is positioned near the outer part of thebelt,a compression section comprising rubber composi tion reinforcedwith fine textile fibers, and an outer cover Yportion enclosing saidbody layerv portions made up of a plurality of rubberized fabric plies,the whole beingvulcanizedV together to form an integral belt, said coverportion comprising spaced shallow grooves along the inner surface ofsaid belt whiclrextend substantially at right Vangles to the side wallsof said belt, said grooves being of less depth than thethickness ofportion during the cover and molded in the cover the final vulcanizationof the belt.

ABRAHAM L. BREED LAND` ER.

